Relationship between 12-lead ECG QT dispersion and 3D-ECG repolarization loop

Detection of QT dispersion on a 12 lead surface electrocardiogram has been proved to be a strong prognostic index of malignant events and it is thought to be closely related to an heterogeneity in the repolarization wavefront This work aims to correlate QT dispersion with the morphology of the spatial T wave loop. Indexes of planarity and geometry are derived from the 3D-ECG repolarization loop with a validated algorithm (CAVIAR). Multiple regression analysis indicates that QT dispersion measured on 12 standard lead is significantly correlated with a loss of planarity and with a wider shape of the loop. QT dispersion is then closely related to a spatial distortion of the cardiac vector during the repolarization phase and can be indirectly evaluated on the 3D electrocardiogram.